Hypodermic syringe



Jan. 26, 1937. M. NEVlN HYBODERMIG SYRINGE Filed July 3, 1926 ill/llama INVENTOR ATTO R N EYS Patented Jan. 26, 1937 UNITED STATES PATENT OFFICE HYPODERMIC SYRINGE Application July 3, 1926, Serial No 120,417

6 Claims.

The object of my invention is to provide a hypodermic syringe arranged for use in connection with a frangible ampul having a breakable point at its front end and a stopper at its rear end, a yielding cushion being provided in the front member of the syringe for the pointed end of the ampul to prevent unintentional breakage thereof,.p1"ovision being also made for the at tachment of either special or standard needles to the said syringe front member.

A further object is to provide a novel form of stopper for the ampul and its coacting plunger head, whereby the stopper may be easily pushed along within the ampul without leakage past the stopper and whereby practically the entire contents of the ampul can be ejected.

Practical embodiments of my invention are represented in the accompanying drawing, in which Fig. 1 represents my improved syringe in side elevation with the parts in the positions they assume when the contents of the ampul have been partially ejected, a special needle being shown attached to the iront member of the syringe.

Fig. 2 represents a longitudinal vertical section taken in the plane of the line IIII of Fig. 1, looking in the direction of the arrows,

Fig. 3 represents a side view of the tapered washer which forms the yielding cushion for the pointed front and end of the ampul within the syringe front member.

Fig. 4 represents a side View of the ampul.

Fig. 5 represents another form of my improved syringe showing the rear member removably secured to the. intermediate member by a screwthreaded engagement therewith instead of the bayonet joint connection shown in Fig. 1; a needle of standard construction being shown attached to the syringe front member through a reducing coupling.

The intermediate member of the syringe is denoted by l, the front member by 2 and the rear member by 3.

The syringe front member 2 is provided with an exteriorly screw-threaded nozzle 4 for the direct attachment of a special hypodermic needle 5 or for the indirect attachment of a standard hypodermic needle 6 through a reducing coupling I.

The frangible ampul is denoted by 8 and it is provided with a breakable pointed front end 9. The rear end of the ampul is provided with a stopper ll] of yielding material having one or more circumferential grooves, in the present instance two grooves, for the reception of a lubricant such, for instance, as glycerine, to facilitate the pushing of the stopper along within the ampul for the ejection of the contents of the ampul when the tip of the pointed end of the ampul has been broken oii. This stopper it": is further provided with a pointed end i2 arranged to be pushed into the pointed end of the ampul for ejecting practically all of the contents of the ampul when the stopper has been pushed to the limit of its forward movement. This stopper is further provided with a central recess 53 for the reception of the head M of the syringe plunger l5, which head is materially smaller in diameter than the bore of the ampul 8. This central recess it enables the head i l of the plunger E5 to partially collapse the surrounding walls of the recess to further facilitate the movement of the stopper along within the ampul and said surrounding walls also prevent the plunger head from contact with the frangibie walls of the arm pul. This plunger 55 is slidable in a longitudinal yielding syringe inner member it which is pressed toward the limit of its forward movement by a spring ll, located within the syringe rear member 3. This plunger it may be provided with a suitable handle it and the intermediate member i may be provided with a suitable coacting handle 69.

In the form shown in Figs. 1 and 2, the syringe rear member 3 is removably attached to the intermediate member I by a bayonet joint connection 2B, 21, while in the form shown in Fig. 5, a screw-threaded connection 22 is provided between the syringe rear member and intermediate member.

A tapered washer 23 of some suitable material, such, for instance, as rubber, is inserted in the tapered bore 24 of the syringe front member 2 around the pointed end 9 of the ampul, which washer serves as a yielding cushion against which the ampul is pressed by the inner member It when the parts are assembled.

To assemble the parts and place the ampul in condition for use, the syringe rear member 3 is removed from the intermediate member and the ampul 8 is inserted into the intermediate member with the tip of its pointed end 9 projecting beyond the needle 4. The tip of the ampul is broken off and the needle attached to the syringe front member. The syringe rear member is then attached to the intermediate member with the plunger and inner member withdrawn to the limit of their rearward movements. The syringe is then ready for use.

When the end of the ampul is broken off a passage is provided through the ampul end wall through which on movement of the piston the anesthetic or other contents of the ampul are injected. These contents pass directly through the end wall of the front member of the frame 2 into the interior canal of the hypodermic needle 5. The ampul is held in place as shown in Fig, 2 of the drawing and a leak-tight joint is formed by a gasket which extends along the end wall of the ampul for a substantial distance towards its fractured opening and substantially occupies the space between the ampul and the inner wall of the front member 2 at approxi mately the entrance to the canal of the needle. When thus held firmly the contents of the ampule will be delivered through the needle substantially without leakage.

It is evident that various changes may be resorted to in the construction, form and arrangement of the several parts without departing from the spirit and scope of my invention; hence, I do not wish to be limited to the particular embodiments herein shown and described, but

What I claim is:-

1. A hypodermic syringe comprising a frangible ampul having a breakable tapered front end, a syringe front member having a tapered bore adapted to receive said tapered front end and an interposed tapered washer covering a major portion of the tapered part of the ampul having an extended contact with the tapered bore of the syringe front member.

2. A hypodermic syringe comprising a frangible ampul having a pointed front end, a stopper for its rear end, and a plunger having its head of greater diameter than its shank and of considerably lesser diameter than the bore of the ampul, said stopper having a central recess for receiving the plunger head and permitting the partial collapse of the surrounding walls of the recess to facilitate the movement of the stopper along within ampul.

3. The combination of a syringe and an ampul, said ampul having a stopper movable therein, said stopper having a central recess therein, a plunger including a head and a shank mounted on said syringe, said plunger head being of a larger size than its shank and of less size than the bore of the ampul, said plunger having its end arranged to seat in said recess and an ampul engaging member surrounding said plunger shank and including a part movable within the syringe to engage the ampul in the barrel.

4. The combination of a syringe and an ampul, said ampul having a stopper movable therein, said stopper having a recess therein, a plunger including a head and a shank mounted on said syringe, said plunger head being of a larger size than its shank and of less size than the bore of the ampul, said head having at least a portion of its sides tapered, said plunger having its end arranged to seat in said recess and an ampul engaging member surrounding said plunger shank and including a part movable within the syringe to engage the ampul in the barrel.

5. In a syringe, a barrel having a closure for one end thereof, said closure including an ampulholding member for engaging the end of an ampul, a plunger, said plunger being movable Within said barrel and through said ampul-holding member, a tip on said barrel, a needle on said tip, said tip having a tapered recess therein, an ampul in said barrel, said ampul including a hol low body portion and an end portion tapered to approximate the taper of said recess, a stopper in said body portion adapted to be engaged by said plunger, a resilient collar adapted to fit said tapered end portion of said body, said resilient collar being of a length greater than the thickness thereof and being adapted to fit within said tapered recess of said tip, whereby when pressure is applied to said ampul by said ampul-holding member said resilient collar will be expanded in said recess without rolling and will engage the wall of said recess and the tapered end portion of the ampul to form a fluid tight seal between said ampul and said tip and releasable means to hold said ampul-holding member in position.

6. A loading assembly for a hypodermic syringe having a tapered forward end, said assembly comprising an ampul having a tapered end and a slidable plug closure at the other end, and a resilient tapered collar of greater length than thickness adapted to fit around and cover a major portion of the tapered part of the ampul, and to serve, when the assembly is in place in said syringe, as a seal between the tapered portion of the ampul and the tapered end of the syringe.

MENDEL NEVIN. 

